//
//  tyu.h
//  oc4-5
//
//  Created by mac on 16-4-5.
//  Copyright (c) 2016年 zhd. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface tyu : NSObject




@property(readonly)NSUInteger protons;
@property(readonly)NSUInteger neutrons;
@property(readonly)NSUInteger electrons;
@property(readonly)NSString *chemicalElement;

-(NSUInteger)massNumber;



@end
